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Low-cost photovoltaic cell
A low-cost photovoltaic cell is a thin-film cell that has a price competitive with traditional (fossil fuels and nuclear power) energy sources. This includes second and third generation photovoltaic cells, that is cheaper than first generation (crystalline silicon cells, also called wafer or bulk cells). The crystalline silicon shortageCharting a Path to Low-Cost Solar has changed the photovoltaic cell economics, making thin films, which use little (1%) or no silicon, more attractive. The cost per watt will be the determining factor for success. The solar industry can potentially reduce costs 40% over the next five years as the silicon shortage ends.Navigant Consulting Fossil fuel grid parity Grid parity, the point at which photovoltaic electricity is equal to or cheaper than grid power, can be reached using low cost solar cells. It is achieved first in areas with abundant sun and high costs for electricity such as in California and Japan.Going for grid parity 2005 article Grid parity has been reached in Hawaii and other islands that otherwise use diesel fuel to produce electricity. George W. Bush had set 2015 as the date for grid parity in the USA.Gaining on the gridThe Path to Grid Parity (Graphic) Speaking at a conference in 2007, General Electric's Chief Engineer predicted grid parity without subsidies in sunny parts of the United States by around 2015. Other companies predict an earlier date.reuters.com Oerlikon Solar has said its facilities will achieve grid parity by 2010 in connection with the opening of the company’s new fully-automated thin-film pilot line at the Solar Valley in Trübbach, Switzerland. First Solar has indicated that its manufacturing cost has fallen in 2009 to 93 cents per watt, down 5% in three months and down 28% in a year. By 2014, it expects to drive down cost per watt to make solar modules to fall to between 52 and 63 cents. The biggest driver of the lower costs is better efficiency.First Solar goes for reduction in manufacturing cost 1366 Technologies enable “solar cheaper than coal”. It is working to commercialize new manufacturing techniques that will increase the efficiency of multicrystalline solar cells. It is doing this with three methods: “Honeycomb” texturing the surface of a cell to increase its surface area and capture more sun; grooving the interconnect wires to allow sunlight to bounce around the module and mitigate the problems of bus-bar shading; and also making the metalization lines — which export the energy from the cell — smaller, cheaper and more efficient. By doing all this with manufacturing techniques that can be integrated into existing manufacturing lines, 1366 hopes to pump out an 18% efficient multicrystalline cell in high volume and produce solar that is competitive with coal by 2013. Abound Solar (formerly known as AVA Solar),http://www.abound.com a start-up formed by a CSU engineering professor, is commercializing a method for manufacturing low-cost, high-efficiency CdTe solar panels.Raabe, Steve. "Solar Plant Seen for State." Denver Post, 9/5/07. China's government has announced generous support for its photovoltaic companies. Two companies, Yingli Green Energy and SDIC Huajing Power, have submitted a bid to build a 10-MW solar power plant to provide electricity to the national grid at a price of RMB 0.69 per kWh or US $0.10 per kWh. At that price, solar energy will be just about as cheap as coal electricity in China. Bottlenecks affecting photovoltaic prices The price of solar panels fell steadily for 40 years, until 2004 when high subsidies in Germany drastically increased demand there, and greatly increasing the price of purified silicon (which is used in computer chips as well as solar panels). One research firm predicted that new manufacturing capacity began coming on-line in 2008 (projected to double by 2009) which was expected to lower prices by 70% in 2015. Other analysts warned that capacity may be slowed by economic issues, but that demand may fall because of lessening subsidies. Other potential bottlenecks which have been suggested are the capacity of ingot shaping and wafer slicing industries, and the number of specialists who coat the wafers with chemicals.Solar rally, The Economist, 28 August 2008 Crystalline silicon Analysts have predicted that prices of polycrystalline silicon will drop as companies build additional polysilicon capacity quicker than the industry’s projected demand. On the other hand, the cost of producing upgraded metallurgical-grade silicon, also known as UMG Si, can potentially be one-sixth that of making polysilicon. Manufacturers of wafer-based cells have responded to thin-film lower prices with rapid reductions in silicon consumption. According to Jef Poortmans, director of IMEC's organic and solar department,Organic solar cells current cells use between eight and nine grams of silicon per watt of power generation, with wafer thicknesses in the neighborhood of 0.200 mm. At 2008 spring's IEEE Photovoltaic Specialists' Conference (PVS'08),PVSC 33 Conference Site John Wohlgemuth, staff scientist at BP Solar, reported that his company has qualified modules based on 0.180 mm thick wafers and is testing processes for 0.16 mm wafers cut with 0.1 mm wire. IMEC's roadmap, presented at the organization's recent annual research review meeting, envisions use of 0.08 mm wafers by 2015. Thin film cells Amorphous silicon solar cell An amorphous silicon (a-Si) solar cell is made of amorphous or microcrystalline silicon and its basic electronic structure is the p-i-n junction. As the amorphous structure has a higher absorption rate of light than crystalline cells, the complete light spectrum can be absorbed with a very thin layer of photo-electrically active material. A film only 1 micron thick can absorb 90% of the usable solar energy. The production of a-Si thin film solar cells uses glass as a substrate and deposits a very thin layer of silicon by plasma-enhanced chemical vapor deposition (PECVD). A-Si manufacturers are working towards lower costs per watt and higher conversion efficiency with continuous research and development on multi-junction thin film solar panels. Anwell Technologies Limited recently announced its target for multi-substrate-multi-chamber PECVD, to lower the cost to USD0.5 per watt. Cadmium telluride solar cell A cadmium telluride solar cell is a solar cell based on a cadmium telluride (CdTe) thin film, a semiconductor layer to absorb and convert sunlight into electricity. Solarbuzzhttp://www.solarbuzz.com has reported that the lowest quoted thin-film module price stands at US$1.76 per watt-peak, with the lowest crystalline silicon (c-Si) module at $2.48 per watt-peak. Copper indium gallium selenide solar cell Copper indium gallium selenide (CIGS) is a direct-bandgap material. It has the highest efficiency (~20%) among thin film materials (see CIGS solar cells). Traditional methods of fabrication involve vacuum processes including co-evaporation and sputtering. Recent developments at IBM and Nanosolar have been targeting to lower the cost by using non-vacuum solution processes. DSSC Dye-sensitized solar cells (DSSCs) are made of low-cost materials and does not need elaborate apparatus to manufacture, so it can be made in a DIY fashion and allows more players to produce it than any other type of solar cell. In bulk it should be significantly less expensive than older solid-state cell designs. It can be engineered into flexible sheets. Although its conversion efficiency is less than the best thin film cells, its price/performance ratio should be high enough to allow them to compete with fossil fuel electrical generation. The DSSC has been developed by Prof. Michael Grätzel in 1991 at the Swiss Federal Institute of Technology (EPFL) in Lausanne (CH). Polymer/organic solar cells Organic solar cells is a relatively novel technology, promising substantial price reduction (over thin-film silicon) and better energy payback time. These cells can be processed from solution, enabling the possibility for a simple roll-to-roll printing process, leading to a cheap, large scale (square kilometers per month) production. Luminescent solar concentrator Luminescent solar concentrators are plastics which concentrate sunlight to a particular spot, where the concentrated solar energy can then be converted by a multi-junction PV solar cell.What is a luminsecent solar concentrator?How a LSC with PV cell worksDescription of the LSC This not only increases efficiency, but also decreases cost, as luminescent solar concentrator panels can be made cheaply from plastics, while PV-cells need to be completely constructed from expensive materials such as silicon. Research is being conducted (amongst others) at universities as RU Nijmegen and TU Delft.Dutch universities working on LSC Massachusetts Institute of Technology researchers have found a way to convert windows into devices that concentrate sunlight for conversion into electricity. They developed a mixture of dyes that can be painted onto a pane of glass or plastic. The dyes absorb sunlight and then re-emit it within the glass in a different wavelength of light, which then tends to reflect off the interior surfaces of the glass. As the light reflects within the glass pane, it tends to get channeled along the length of the glass to its edges, where it is emitted. The sunlight is concentrated by a factor of about 40, allowing solar cells that are optimized for such concentrated sunlight to be mounted along the edges of the window. The unique optics of the approach yields a cheap solar concentrator that does not need to be pointed toward the sun, as is needed for lens-based concentrators. The process will be commercialized by Covalent Solar within the next 3 years. Covalent Solar: Technology Other concentrating photovoltaics Compared to conventional flat panel solar cells, concentrating photovoltaics (CPV) is advantageous because the solar collector is less expensive than an equivalent area of solar cells. CPV system hardware is typically priced around 3 USD/Watt, whereas silicon flat panels are commonly 5 USD/Watt (not including any associated power systems or installation charges). Semiconductor properties allow solar cells to operate more efficiently in concentrated light, as long as the cell junction temperature is kept cool by a suitable heat sinks. CPV operates most effectively in sunny weather, since clouds and overcast conditions create diffuse light which essentially can not be concentrated. Nanotechnology and infrared The technology of solar arrays of nanoantennas is expected to be highly efficient with regard to capturing energy (80% efficiency) and in the process of creating the device (cents per yard).Nanoantennas: Solar arrays that absorb energy even in the dark! February 11, 2008 Small square spirals of metal can be printed on plastic sheets, using roll-to-roll machinery. . The antennas can capture energy associated with infrared radiation, which reaches the earth from the sun during the day and is re-emitted by the earth at night. Commercial solar panels usually transform less that 20% of the usable energy that strikes them into electricity, but individual nanoantennas can absorb close to 80%. The circuits themselves can be made of a number of different conducting metals, and the nanoantennas can be printed on thin, flexible materials like polyethylene, a plastic that's commonly used in bags and plastic wrap. Double-sided panels could absorb a broad spectrum of energy from the sun during the day, while the other side might be designed to take in the narrow frequency of energy produced from the Earth's radiated heat. High Gain Solar High Gain Solar (HGS) arrays incorporate silicon cells, durable reflector materials and single-axis tracking. HGS delivers ten times more energy per gram of silicon than traditional flat panel systems in sunny locations.HGS architecture See also *Grooving *Honeycomb *Indoor light *Investment in renewable energy *Lower-cost deposition *Multijunction cell *Nanoflake *PEGE *Printed electronics *Roll-to-roll processing *Silicon thin-film cell *Stacked solar cell *Thermophotovoltaics References External links *Current Progress in Future Opportunities for Thin Film Solar Cells (NREL). *Breakthrough claimed by Korean researchers *Solar Shootout in the San Joaquin Valley. *Oerlikon discusses path to $0.70/W thin-film PV panels *Photovoltaic technologies beyond conventional silicon (IDTechEx). *Charting a Path to Low-Cost Solar. *Business leaders: Make renewable energy cheaper (International Herald Tribune). *The Thin Film Revolution. *Affordable Solar *Crystal Clear, an EU FP6 Integrated Project. *Will Emerging Markets Make Renewable Energy More Democratic? *July 2009 solar price survey shows new record low in Europe. *Creating (Not Overly) Disruptive Changes in Solar Manufacturing. Category:DIY Category:Electric power infrastructure Category:Energy conversion Category:Infrared photovoltaics Category:Photovoltaics Category:Renewable-energy economy Category:Semiconductor devices Category:Solar concentrating systems Category:Thin-film cells Category:Appropriate technology